In protecting the components on aircraft from heat damage due to an engine fire, blankets formed from insulating material have been known and used in the past. Generally, blankets of conventional construction which have been used for this purpose require extensive and oftentimes bulky support systems to keep the blankets in their operating positions. Such support systems include frames, sheet metal backing members, fasteners and the like. These systems add considerably to the weight of an aircraft, and it is generally the aim in design of all structural parts of an aircraft to minimize weight if at all possible.
A fire barrier composition material has been disclosed in U.S. Pat. No. 4,225,483 in which the material is capable of withstanding a 2,000.degree. F. flame temperature. However, the composition material of this patent relates to the enhancement of a resin impregnated in a graphite fiber or glass cloth to stabilize any char that forms when the material is subjected to a flame. Other disclosures relating to composite structural members formed from a number of adjacent layers include U.S. Pat. Nos. 3,573,123, 3,769,144, 3,993,829 and 4,256,790.
None of the foregoing patents discloses or suggests a heating insulating blanket in which one of the layers of the assembly is impregnated with a resin capable of curing so that layer will define a heat and flame resistant, lightweight fireshield yet the layer will be sufficiently rigid to be self-supporting or to form a support for other layers of insulating material so as to make it suitable for use in aircraft and other applications. Because of this lack, a need has arisen for an improved heat insulating blanket which has the foregoing desirable features, and the present invention satisfies this need.